/*
* Copyright (C) 2012 Google Inc. All rights reserved.
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* 1. Redistributions of source code must retain the above copyright
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#ifndef AudioScheduledSourceNode_h
#define AudioScheduledSourceNode_h
#include "modules/webaudio/AudioSourceNode.h"
namespace WebCore {
class AudioBus;
class AudioScheduledSourceNode : public AudioSourceNode {
public:
// These are the possible states an AudioScheduledSourceNode can be in:
//
// UNSCHEDULED_STATE - Initial playback state. Created, but not yet scheduled.
// SCHEDULED_STATE - Scheduled to play (via noteOn() or noteGrainOn()), but not yet playing.
// PLAYING_STATE - Generating sound.
// FINISHED_STATE - Finished generating sound.
//
// The state can only transition to the next state, except for the FINISHED_STATE which can
// never be changed.
enum PlaybackState {
// These must be defined with the same names and values as in the .idl file.
UNSCHEDULED_STATE = 0,
SCHEDULED_STATE = 1,
PLAYING_STATE = 2,
FINISHED_STATE = 3
};
// This helper class handles the lifetime of an AudioScheduledSourceNode with an onended event
// listener. This keeps the node alive until the event listener is processed.
class NotifyEndedTask {
public:
NotifyEndedTask(PassRefPtr<AudioScheduledSourceNode> scheduledNode);
void notifyEnded();
private:
RefPtr<AudioScheduledSourceNode> m_scheduledNode;
};
AudioScheduledSourceNode(AudioContext*, float sampleRate);
// Scheduling.
void start(ExceptionState& exceptionState) { start(0.0, exceptionState); }
void start(double when, ExceptionState&);
void stop(ExceptionState& exceptionState) { stop(0.0, exceptionState); }
void stop(double when, ExceptionState&);
unsigned short playbackState() const { return static_cast<unsigned short>(m_playbackState); }
bool isPlayingOrScheduled() const { return m_playbackState == PLAYING_STATE || m_playbackState == SCHEDULED_STATE; }
bool hasFinished() const { return m_playbackState == FINISHED_STATE; }
EventListener* onended() { return getAttributeEventListener(EventTypeNames::ended); }
void setOnended(PassRefPtr<EventListener>);
protected:
// Get frame information for the current time quantum.
// We handle the transition into PLAYING_STATE and FINISHED_STATE here,
// zeroing out portions of the outputBus which are outside the range of startFrame and endFrame.
//
// Each frame time is relative to the context's currentSampleFrame().
// quantumFrameOffset : Offset frame in this time quantum to start rendering.
// nonSilentFramesToProcess : Number of frames rendering non-silence (will be <= quantumFrameSize).
void updateSchedulingInfo(size_t quantumFrameSize,
AudioBus* outputBus,
size_t& quantumFrameOffset,
size_t& nonSilentFramesToProcess);
// Called when we have no more sound to play or the noteOff() time has been reached.
virtual void finish();
static void notifyEndedDispatch(void*);
PlaybackState m_playbackState;
// m_startTime is the time to start playing based on the context's timeline (0 or a time less than the context's current time means "now").
double m_startTime; // in seconds
// m_endTime is the time to stop playing based on the context's timeline (0 or a time less than the context's current time means "now").
// If it hasn't been set explicitly, then the sound will not stop playing (if looping) or will stop when the end of the AudioBuffer
// has been reached.
double m_endTime; // in seconds
bool m_hasEndedListener;
static const double UnknownTime;
};
} // namespace WebCore
#endif // AudioScheduledSourceNode_h